1. Field of the Invention
The present invention relates to a pedal assembly, more particularly to a bicycle pedal assembly.
2. Description of the Related Art
A conventional bicycle pedal assembly is adapted to be mounted on a bicycle pedal shaft and to engage a cleat unit fixed to a bottom surface of a sole of a cyclist's shoe.
Referring to FIG. 1, a conventional bicycle pedal assembly 10 is shown to include a rectangular pedal body 11 having front and rear portions 111a, 111b along a treading direction, and a central tubular portion 112 extending between and parallel to the front and rear portions 111a, 111b. The central tubular portion 112 has a co-axial spindle 12 for mounting on a bicycle pedal shaft (not shown). The front and rear portions 111a, 111b and the central tubular portion 112 cooperatively define front and rear accommodating spaces 113a, 113b. Each of the upper surface of the front portion 111a and the lower surface of the rear portion 111b is formed with a receiving cavity 116 (only the one in the front portin 111a is shown).
The bicycle pedal assembly 10 further includes a pair of anchoring units 20, each having two anchoring members 21 accommodated in the respective one of the front and rear accommodating spaces 113a, 113b. Each of the anchoring units 20 further includes two biasing members 22, an adjusting plate 23, an adjusting bolt 24, a mounting axle 25, and a positioning plate 26. Each of the anchoring members 21 has two side walls 211 which define a space to receive a respective one of the biasing members 22. Each side wall 211 has a through hole 212 for passage of the mounting axle 25 therethrough. Each of the front and rear portions 111a, 111b has two aligned mounting holes 114 and 115. The axles 25 pass through the mounting holes 114 and 115 and the through holes 212 formed in the side walls 211 of the anchoring members 21 to pivotably mount the respective one of the anchoring members 21 on the front and rear portions 111a, 111b, respectively, with each of the biasing members 22 being sleeved on the respective one of the axles 25. The biasing members 22 bias the anchoring members 21 against rotation when a rearward end 33 of a cleat unit 30 (see FIGS. 2 and 3) presses on the anchoring members 21. The cleat unit 30 is fixed to a bottom surface of a cyclist's shoe (not shown in the drawings) by a locking member 31, as shown in FIGS. 2 and 3.
Referring to FIGS. 2 and 3, when the biasing members 22 are mounted on the respective one of the anchoring members 21, a secured end 221 of each of the biasing members 22 abuts closely against the respective one of the anchoring members 21, and an adjusting end 222 thereof is secured to the adjusting plate 23. The adjusting bolt 24 is threaded into a threaded hole formed in the adjusting plate 23 for adjusting the tension of the biasing members 22. When the adjusting bolt 24 is threaded into or out relative to the adjusting plate 23, the adjusting plate 23 will move toward or away from the tubular portion 112 along the adjusting bolt 24, thereby resulting in the concurrent movement of the adjusting end 222 which is secured on the adjusting plate 23. As a result, the tension of the biasing members 22 can be adjusted.
The positioning plate 26 of each of the anchoring units 20 is mounted fixedly on the tubular portion 112 by a pair of screws 27. Each of the positioning plates 26 has a contacting base for contacting the bottom surface of the cleat unit 30, a front stop portion 261 which extends upwardly from the contacting base and which is received in the respective one of the receiving cavities 116, and a pair of rear stop portions 262. The rear stop portions 262 abut against the anchoring members 21.
In order to engage the cleat unit 30 to the pedal assembly 10, the forward end 32 of the cleat unit 30 first engages the front stop portion 261 of the positioning plate 26. Then, the cleat unit 30 is rotated about the forward end 32 to move the rearward end 33 thereof into engagement with the anchoring members 21. Since the anchoring members 21 are pressed away by the rearward end 33 of the cleat unit 30, a biasing force generated by the biasing members 22 will be applied to the rearward end 33 of the cleat unit 30. As a result, the cleat unit 30 is clamped between the positioning plate 26 and the anchoring members 21. In order to disengage the cleat unit 30 from the bicycle pedal assembly 10, the cleat unit 30 is rotated about the forward end 32 thereof to slide the rearward end 33 relative to the anchoring members 21. As a result, the cleat unit 30 can be released from the positioning plate 26 and the anchoring members 21.
The bicycle pedal assembly 10, though capable of functioning to releaseably engage the cleat unit 30, has following disadvantages:
1. When the cleat unit 30 engages the bicycle pedal assembly 10, since the bottom surface 34 of the cleat unit 30 closely contacts the upper surface of the positioning plate 26, as shown in FIG. 3, it takes the cyclist more effort to release the cleat unit 30 from the bicycle pedal assembly 10.
2. Since the bottom surface 34 of the cleat 30 contacts closely the upper surface of the positioning plate 26, disengagement of the cleat unit 30 from the pedal assembly 10 can not be smoothly performed.
3. Since the bottom surface 34 of the cleat unit 30 contacts closely the upper surface of the positioning plate 26, dirt is easily stuck between the positioning plate 26 and the biasing members 22, between the biasing members 22 and the anchoring members 21, and between the cleat unit 30 and the positioning plate 26. Thus, cleanliness of the pedal assembly is hard to maintain, and precise movement of the moving parts of the pedal assembly 10 is not ensured.
4. Since each of the anchoring units 20 includes two anchoring members 21 and a positioning plate 26 for engaging the cleat unit 30, the number of components that constitute the bicycle pedal assembly 10 is relatively large, and the structure of the pedal assembly 10 is complicated, thus resulting in a time-consuming assembly procedure and in high production costs.
In view of the above disadvantages, it would be desirable to provide a less complicated bicycle pedal assembly which requires less effort to release the cleat unit from the pedal assembly and which is easy to maintain.